Method

Heat one tablespoon of oil in a frying pan and cook the shallots or onion for five minutes.

Add the mushrooms with a sprinkle of salt and cook for 10 minutes.

Put this into the bowl of a food processor along with the walnuts, breadcrumbs, egg and soy sauce and process together.

Shape into four patties.

Heat the remaining oil in a frying pan and cook the patties for five minutes each side.

In the meantime, heat the grill. Toast the buns if you like and when the patties are cooked, place two slices of cheese on each patty and melt under the grill before building your burger with your favourite additions.